1. Field of the Invention
The invention relates generally to the use of human beta defensins, lysozyme, and lactoferrin as a new class of non-antibiotic antimicrobials. More specifically, the invention relates to the use of these antimicrobials for the treatment of otitis media and paranasal sinusitis.
2. Description of the Related Art
The rapid worldwide increase in antibiotic resistance among pathogens has given rise to an urgent need to develop new and innovative non-antibiotic approaches to prevent and manage disease. Otitis media (OM) and sinusitis are two very common infections which are difficult to treat for a number of reasons, including antibiotic resistance. OM is the most prevalent infectious disease affecting young children, and the major cause of conductive hearing loss among this group. OM is also the leading indication for antibiotic therapy. OM results in 31 million annual visits to physicians' offices and is estimated to have a yearly cost exceeding $5 billion.
OM occurs along a continuum. For example, OM with effusion characterized by fluid pathology can lead to chronic OM plus chronic mastoiditis, characterized by the presence of intractable tissue pathology such as cholesteatoma, cholesterol granuloma or granulation tissue. The literature defines chronic OM as having a tympanic membrane perforation and otorrhea. Amongst many other sequelae, which can result from the continuum, an important common one is chronic silent OM. This overlooked entity which includes pathology beneath an intact tympanic membrane is commonly seen in patients. Labyrinthitis is the most frequent complication of chronic OM.
Most cases of OM are caused by one of three major pathogens, Streptococcus pneumoniae (S. pneumoniae) (30-40%), non-typeable Haemophilus influenzae (NTHi) (30%) and Moraxella catarrhalis (M. catarrhalis) (20%). These are the same pathogens that can also cause meningitis. Typically, these infections are treated with antibiotics. In the past three decades, there has been a dramatic worldwide increase in antibiotic resistance in OM pathogens. This has resulted in a reduction of the number of effective antibiotics for this disease and begun to pose a major public health threat. Thus, the use of antibiotics is becoming more complicated as resistance increases, necessitating the testing of microbes before treatment, which can sometimes fatally delay the necessary treatment. In addition, wide antibiotic use is further contributing to the problem of resistance. The need to identify new antibiotics is causing the price of these substances to be so high as to be prohibitive in some cases. Therefore, there is a need for new, innovative, and cost-effective approaches to prevent and manage these diseases. It is believed that the defenses of the Eustachian tube (E tube) and the middle ear (tubotympanum) help to maintain the sterility of the middle ear under normal conditions. To this end, an understanding of the mechanisms that protect the tubotympanum (the middle ear and Eustachian tube) from invading organisms and determine the role that they play in the pathogenesis of OM could prove useful in identifying a new treatment.